This invention relates to an antibiotic substance and to a method for its production. In particular, it relates to a broad spectrum antibiotic produced by culturing Xanthomonas albilineans in an aqueous nutrient culture medium.
During our study of leaf scald disease of sugarcane (Saccharum officinarum L.) caused by the xylem-invading bacterium Xanthomonas albilineans (Ashby) Dowson, it appeared likely that the organism may produce a diffusible phytotoxin. We cultured chlorosis-inducing X. albilineans (Ashby) Dowson strain LS2, an original isolate from diseased sugarcane from Hawaii, in attempting to demonstrate a phytotoxin. Although the production of antimicrobial agents by the genus Xanthomonas has not been previously reported, we were able to isolate a mixture of antibiotic substances and to isolate and purify the major antibacterial component of the mixture. This antibiotic, which we have designated by the arbitrary name albicidin, has been found to inhibit the growth of a broad spectrum of microorganisms pathogenic to man and animals.